With the development of electronic information technologies, data stored by users in a database is ever-increasing. To ensure security and stability of the data, a lot of data maintenance/recovery technologies are derived, where a multi-copy data storage technology is a common data maintenance/recovery technology.
In an existing multi-copy data storage technology, multiple same copies are generated on a basis of data, and the multiple same copies are separately stored in different databases or backup nodes. For example, data that needs to be backed up may be copied to generate three same copies, and each copy is the same as the data that needs to be backed up. The three same copies are separately stored in a node 1, a node 2 and a node 3; the node 1, the node 2 and the node 3 have been networked, and may perform data exchange. When the copy on one node is damaged, the copy is recovered using the correct copy on another node. For example, when the data on the node 3 is damaged due to a fault occurring on the node 3, the data on the node 3 is recovered using the correct data on the node 1 or node 2, which ensures that the three copies are available and enhances data reliability.
Problems in the prior art are as follows. In some cases, all copies may be damaged. For example, when the copies in the node 1, node 2 and node 3 are all damaged, the copies cannot be recovered, so that the data that is backed up is permanently damaged, and this brings losses to a user due to low security of the data that is backed up.